Method and device for the portioned packaging of a food mass

ABSTRACT

The invention relates to a method for the portioned packaging of a food mass that is at least substantially incompressible, in particular of processed cheese, and that is filled as a flowable mass into a tubular sleeve comprising a thermoplastic plastic film, wherein the thermoplastic plastic film of the sleeve enclosing the food mass is deformed in a mold into individual units each defining a portion by forcing the food mass out of sealing areas, such that the units arranged one behind the other are delimited with respect to each other by means of sealing in the sealing area and are subsequently separated from one another.

The invention relates to a method for the portioned packaging of an atleast substantially incompressible food mass, of processed cheese inparticular, which is filled as a flowable mass into a tubular wrappingcomprising a thermoplastic plastic film. The invention further relatesto a device for carrying out the method.

Various methods are known for the portioned packaging of such a foodmass. In some methods, the food mass is poured into shells, which arepreformed of a stable film, more particularly plastic. The individualshells filled with the food mass are subsequently closed and separatedfrom one another. The disadvantage of this solution is that a separatetool or even a separate machine is required for each working step, moreparticularly preshaping, filling, closing and separating. In addition,the portioned filling of preshaped packages with such a food mass isrelative complex in terms of adjustment.

Basically, three methods are known for packaging processed cheese: It isknown, for instance, to bring the processed cheese into slice form andto stack these individual slices on top of one another, “slice onslice”. It is also known to make individually packaged slices(“individual wrapped slices”, IWS). To this end, a film tube is filledwith processed cheese and smoothed into a strip before it is subdividedinto individual slices by displacement, sealing and cutting. Another wayto package processed cheese is to enclose individual portions inaluminum foil. Such portions are known as triangular shapes, a pluralityof which is placed together in a circle in one common outer packaging.The individual portions can be provided with a string, as the tear-openaid, which cuts through the foil. Such portioned packaging in aluminumfoil is relatively complex.

The problem addressed by the present application is therefore that ofproviding a method for the portioned packaging of a food mass, moreparticularly processed cheese, in which the individual packages of thefood mass can be manufactured in a simple and low-cost manner in variousshapes and which are easy for the consumer to handle. A correspondingproblem addressed by the invention is that of providing a device forimplementing the method.

These problems are solved by a method having the features of claim 1 andby a device having the features of claim 7. Advantageous embodiments arementioned in the dependent claims.

The significant fundamental idea of the invention is to fill the foodmass into a film tube and subsequently deform it by deep drawing whilemaintaining the presence of the food mass. To this end, the food mass isbasically displaced out of regions of the completely filled tube intoregions in which deep drawing takes place quasi simultaneously. Aseparate deep-drawing punch is not required, however. The food massfunctions as a punch and presses the film into the mold of the tool. Themass that is excessive in the regions of the displacement finds space inthe newly formed regions. To this end, according to the invention, thethermoplastic plastic film of the wrapping enclosing the food mass isreshaped in a mold into individual units, each defining a portion, withdisplacement of the food mass out of sealing areas. Said units disposedone behind the other in a chain are delimited from one another by way ofsealing in the sealing area and are subsequently separated from oneanother.

Such a unit is also referred to in the following as a cavity filled withthe food mass. The cavity defining a portion of the food mass istherefore formed, according to the invention, in the film strip, whichis already filled. The flowable food mass enclosed by the film stripthereby completes the shaping of the film layer and assumes the shape ofthe cavity. The shaping of the film strip and a portioning of the foodmass are therefore concomitant.

The method according to the invention makes it possible to manufactureeasy-to-handle individual packages in an automated manner. The methodcan replace the subsequent filling of preformed shells. As a result, theproduction of individual packages filled with food mass is greatlysimplified and product output is markedly increased. Due to thesimultaneous shaping of the film tube and the food mass, the method issuitable more particularly for the portioned packaging of processedcheese, since processed cheese is particularly easy to handle becausethe viscosity thereof can be adjusted via temperature. The method makescontinuous production possible. At the same time, it offers highvariability in terms of the possible packaging shapes. The cavities canbe formed in the filled film strip in nearly any shape and, due to thethree-dimensional orientation thereof in particular, they offer a greatdeal of freedom for product design.

It is particularly advantageous that the shaping of the filled filmstrip, according to the invention, can be integrated into existingproduction systems for packaging food masses. It is therefore possibleto retrofit or expand previously used machine lines for the new method.

In a preferred embodiment, both film layers of a double-layer film tubefilled with food mass are molded. By forming opposing cavities in thedouble-layer film strip, it is possible to increase the total volume ofthe individual package that is available. Shaping the double-layer filmstrip on both sides also makes it possible to obtain a symmetricaldesign of the top part and the lower part of the individual packaging.For the case of an asymmetrical design, a top part of the forming meansis designed smooth, for example, while the lower part comprises shapingcavities.

A vacuum is preferably applied in a forming means to support theformation of the cavities in the film layer. The vacuum induces a typeof deep-drawing effect on the film layer. It is applied while the moldsegment of the forming means closes in the sealing area of thedouble-layer film strip. The vacuum is deactivated before the shapingmeans is opened. The film layer is thereby not only pressed into themold segment, it is also drawn in via suction. It comes to line thewalls thereof and assumes the shape thereof. The vacuum induces aprecise molding of the predefined shape by way of the thermoplasticfilm.

The food mass is thereby not only displaced out of the sealing areas, itis also suctioned into the mold segments. It follows the shaping of thefilm layer and fills the mold segment. Only a slight amount of food massremains in the sealing area due to the combination suction anddisplacement effect acting on the food mass, thereby simplifying thesubsequent sealing of the film layers in the sealing area. It isparticularly advantageous when the vacuum is adapted to the food mass interms of level and duration.

Temporary and local heating of the thermoplastic plastic film supportsthe formation of the cavities in the film strip. To this end, theregions of the forming means coming in contact with the film to bereshaped are heated.

Thermoplastic plastics of different types and film thicknesses can beprocessed using the method and the device. Films made of PE, PET and PPare suitable in particular. The preferred film thickness is between 20μm and 100 μm. The method also makes it possible to use film tubes madeof film strips of different materials. Film strips made of thermoplasticplastic and aluminum foil can be combined, for example.

Preferably, a separating segment of the forming means is first movedinto the food mass enclosed by the film strip. Said separating segment,which is designed as a type of hold-down device, moves into theproduction strand before the individual packages are shaped. Ittherefore delimits the part to be reshaped from the rest of the filmtube. This subdivision of the product strand defines the region of thefilled film tube that is available for the forming process. The segmentprevents food mass from flowing out of the rest of the production strandinto the part of the film strip to be reshaped while the cavities arebeing formed. It is thereby possible to minimize fluctuations in thevolume of the individual packages that are produced.

To ensure that the product strand becomes detached from the formingmeans, a vacuum is preferably applied to the cavities of the formingmeans. To this end, it is advantageous to use the vacuum connection toalso supply vacuum.

The forming means preferably also comprises a means for sealing thesealing area located between the consecutive hollow shapes. Since theforming means not only forms the cavities in the filled film strip, butalso seals the sealing area, this working step can be combined in onetool. It is therefore easier to change the shape of the individualpackages. Such shape changes usually involve changing the shape andposition of the sealing area between the individual packages. When thepackaging shape is changed, the effort required for set up at thepackaging system is therefore reduced.

In a particularly preferred embodiment, the sealing area separating thecavities is sealed using ultrasound. Using ultrasound for sealing hasthe great advantage over sealing using heat that a seam sealed usingultrasound is easier to re-open later, that is, it has better“pealability”. In addition, the ultrasound displaces any remainingquantities of food mass out of the sealing area. A product inclusion inthe sealing seam is prevented. This ensures uniform strength of thesealing seam. In addition, a product inclusion in the sealing area isperceived by the customer as an impairment of quality. The clean sealingseam increases the appearance of quality of the final product. Thesealing by way of sonotrode and sealing anvil can take place in aseparate working step. The forming means itself, more particularly thelateral delimitations of the shaping cavity thereof moving into thesealing area, are preferably designed as a sonotrode. The sealingcomponents are therefore integrated into the forming means.

At the end of the process, the film strip is cut in the sealing area.The packages of food mass, which have been separated from one another,are then fed individually to the further packaging process. Theindividual working steps of the shaping, sealing and separation of theindividual packages are preferably combined in direct succession. Inorder to retrofit the production system for another packaging shape, itis therefore only necessary to replace the forming means and theseparating device. In a particularly preferred embodiment, theseparating device is part of the forming means.

In a further particularly preferred embodiment, the food mass is cooledbefore the filled film strip is shaped. In contrast to pouring a liquidfood mass into a preshaped packaging mold, when the cavities are formedaccording to the invention, the food mass is pressed therein and ispreferably also suctioned therein. The consistency of the food mass istherefore not required to be liquid but merely flowable in order to fillthe cavities formed in the film strip. The food mass has already cooledto a great extent when the cavities are formed in the film layer. It istherefore possible to eliminate complex cooling of the shaped individualpackage in order to prevent deformations in the further course of theproduction process, and to eliminate having to fill secondary packages.In order to perform cooling before shaping, the food mass is preferablyguided along a cooling path using cooling belts in a manner known perse, or said food mass is directed through a cooling water bath. Thisensures uniform cooling of the food mass. The film can be suppliedbefore or after cooling.

In a further particularly preferred embodiment, the edge regions of thetwo film layers overhanging at a longitudinal sealing seam form anopening tab for opening the package. The two film layers are connectedto one another via the longitudinal sealing seam before the cavities areformed. Depending on how the double-layer film strip was placed, itcomprises one or two longitudinal sealing seams. If a single film isplaced so as to form a double-layer film strip, it comprises alongitudinal sealing seam on one side, which connects the lateral endregions of the two film layers to one another. The variant of adouble-layer film strip formed of two film layers comprises longitudinalsealing seams on both sides. The film layers are dimensioned in such away that film edge regions of the joined film layers overhang after thelongitudinal sealing seam is sealed. Pulling the overhanging film edgeregions apart first opens the longitudinal sealing seam and, as pullingcontinues, opens the sealing areas of the individual package. Thepackaging portion can thereby be easily opened completely and thecontents thereof can be removed from the packaging without leaving anytraces behind.

The overhanging film edge regions are preferably cut off in such a waythat the remaining film edge region of the two film strips has the shapeof a tab protruding from the individual package. The tab shape isintuitively recognized by the customer as an opening mechanism for theindividual package, and therefore no further instructions on the packageare required.

In a further preferred embodiment, the two-layer film strip is incontinuous forward motion. This creates an endless, continuouslyself-renewing product strand of the filled film strip. Automaticrepositioning of the forming means during the forming process makes itpossible to continuously manufacture individual packages of the foodmass with correspondingly high product output.

The method or the device according to the invention makes it possible tomanufacture packaging portions in highly diverse shapes. In addition tothe popular cheese wedge shape familiar to the consumer, it is alsopossible to form square or rectangular cavities in the film strip. Thecavities can be formed in one film strip or in both film stripssymmetrically or asymmetrically with respect to one another. A furthervariable is the material that is selected for the films. Thepossibilities for variation therefore range from a symmetrical packagehaving film strips made of plastic that are identically shaped on bothsides and a sealing seam encircling the package in the center, to apackage shaped on one side and having an off-center sealing seam, thenon-reshaped aluminum foil strip of which closes the package in themanner of a cover.

In contrast to the known packages made of aluminum foil, the use of atransparent plastic film provides the consumer with a direct view of thepackaged product. Additions such as herbs or nuts need not be onlyindicated on the label; the customer can even see them in the productitself. By coloring the film strip specifically according to type, it ispreferably possible to identify the contents of the package.

An embodiment of the invention is described in the following byreference to FIGS. 1 to 11. Shown are

FIG. 1: shows an opened forming tool with a still undeformed productionstrand of the enclosed food mass;

FIG. 2: shows a sectional drawing along the line A-A of FIG. 1;

FIG. 3: shows the closing forming tool as it begins to move into theproduct strand;

FIG. 4: shows a sectional drawing along the line B-B of FIG. 3;

FIG. 5: shows the closing forming tool with a closed separating segmentthat has penetrated the product strand;

FIG. 6: shows a sectional drawing along the line C-C of FIG. 5;

FIG. 7: shows the forming tool after completion of the forming process;

FIG. 8: shows a sectional drawing along the line D-D of FIG. 7;

FIG. 9: shows a hold-down device of the forming tool;

FIG. 10: shows a base plate of the forming element comprising moldsegments;

FIG. 11: shows a schematic representation of the various shaping stepson the product strand.

FIGS. 1 to 8 show a forming means according to the invention in the formof a forming tool 1. The forming tool is depicted in a series of variousphases of the process of forming the film strip 2 filled with food mass.

In FIGS. 1 and 2, the forming tool 1, which comprises an upper part 3and a lower part 4, is open and has no contact with the productionstrand of the film strip 2. The upper part 3 and the lower part 4 of theforming tool 1 are oriented toward the top side and the underside,respectively, of the production strand and are disposed opposite oneanother in a mirror-image manner. The upper part 3 and the lower part 4are of substantially identical construction, and so informationregarding features or movements of one part 3, 4 of the forming tool 1always also relate to the other part 3, 4 in a mirror-image manner.

Each part 3, 4 of the forming tool 1 comprises a base plate 5 and a moldplate 6, which is disposed on the side of the base plate 5 facing theproduction strand and is detachably connected thereto. A separatingsegment 7, as a type of hold-down device, projects from the part 3, 4 inthe direction of the production strand. The base plate 5 and thehold-down device are connected to one another via a guide 8. The guide 8is preloaded via springs 9 and permits the hold-down device to moverelative to the base plate 5. The base plate 5 further comprises avacuum and compressed air connection 10, which is connected to a hollowchamber 11 incorporated in the mold plate 6. A vacuum is applied at amold segment of the forming tool 1 via the hollow chamber 11.

The hollow chamber 11 is delimited on the product-strand side by aninsertable base 12, which is separated from the base plate 5 by way of aspacer sleeve 13. The insertable base 12, in combination with webs 14 ofthe mold plate 6 protruding laterally from the insertable base 12 in thedirection of the production strand, forms a mold segment 15, which isopen toward the filled film strip 2 and into which the film strip 2 isformed. The mold segment 15 therefore forms a female mold for the filmstrip 2 filled with the food mass 16.

The film strip 2 filled with food mass 16 comprises two film layers 17,18, which are connected to one another on both sides via longitudinallyextending sealing seams 19. Film edge regions 20 protrude from thedouble-layer film strip 2 along the longitudinal sealing seams 19. Themold plate 6 comprises two temperature-controlled cartridge heaters 21for the temporary and local heating of the thermoplastic film layer 17,18.

FIGS. 3 and 4 show the forming tool 1 at the beginning of the closingprocess. At this point in time, an outer surface of the hold-down device7 is located at the level of the still non-deformed product strand ofthe filled film strip 2. The hold-down device 7 comprises a heatingelement, which is not shown here, in order to heat the thermoplasticplastic film to be deformed. The heated hold-down device 7 is offset oneither side with respect to the enclosed food mass 16 and is disposedabove the film edge regions 20 of the double-layer film strip 2. Toprevent the film edge region 20 from becoming heated by contact with theheated hold-down device 7, the hold-down device 7 comprises alongitudinally extending insulating element 21 on both sides, whichexternally adjoins a longitudinal web 22 of the hold-down deviceprotruding in the direction of the production strand. The hold-downdevice 7 also comprises two cross webs, which are not shown here andextend transversely overall with respect to the production strand, saidcross webs contacting the double-layer film strip 2 in this position ofthe closing process.

In FIGS. 5 and 6, the hold-down devices 7 are closed by the upper part 3and the lower part 4 of the forming tool 1, and therefore the film edgeregions 20 are held between the longitudinal webs 22 and the insulatingelements 21. In this position of the forming tool, the cross webs of thehold-down devices 7 have fully penetrated the product strand. The crosswebs, which are disposed at the beginning and at the end of thehold-down device 7 relative to the production strand, therefore seal theregion of the production strand to be deformed by the forming tool 1.

FIGS. 7 and 8 show the forming tool 1 with the upper part and the lowerpart 3, 4 completely closed. When the vacuum is applied into the moldsegments 15, the pressure plate 5, together with the mold plate 6, inboth parts 3, 4 moves in the direction of the production strand. Theheated webs 14 of the mold plates 6 thereby penetrate the product strandin opposition, deform the thermoplastic film layer 17, 18 at this point,and displace the food mass 16 located in this region of the productstrand. The food mass 16 presses the film layers 17, 18 into the moldsegments 15. The food mass 16, which is at least nearly incompressible,functions as a deep-drawing punch that presses the film layer 17, 18into the mold segments 15. Cavities 23, each defining a portion of thefood mass 16 and following one another individually, are thereby formedin the film layers 17, 18.

In addition, the film layer 17, 18 is drawn against the heatedinsertable base 12 via the vacuum present in the mold segment 15. Thevacuum is applied after the hold-down device 7 has fully penetrated theproduct strand. The strength and the duration of the vacuum are adaptedto the food mass. The food mass 16, which is still flowable and has beendisplaced from the region of the closing webs 14, completely fills thecavity 23 that forms.

In the exemplary embodiment described here, two opposed cavities 23 forma single portion of the food mass 16 in each case. The shape of theportion is defined by the mold segments 15 of the parts 3, 4.

The mutually impacting webs 14 of the mold plates 6 press the filmlayers 17, 18 together and define a sealing area 24 encircling theindividual packages. The sealing area 24 is sealed using an ultrasonicsealing method known per se in order to permanently shape the individualpackages. The webs 14 function as a sonotrode (welding horn), andtherefore the sonotrode and sealing anvil sealing components areintegrated in the forming tool. The two working steps can also becarried out by two tools that follow one another in the productionprocess.

After the individual packages are fully formed, the vacuum in the moldsegment 15 is no longer maintained. The parts 3, 4 of the forming toolmove apart from one another and release a strand of fully formed,consecutive individual packages of the food mass 16.

During the method steps described by reference to FIGS. 1 to 8, theforming tool moves at a speed v_(wx), which corresponds to the speedv_(p) of the continuously moving production strand. After opening, theforming tool 1 moves along the production strand opposite the conveyancedirection back into a starting position, from which a new work cyclestarts. When the forming tool 1 closes, the rear—relative to theproduction direction—web 25 of the hold-down device 7 moves from thestarting position of the forming tool 1 to the boundary of the strandsection that was formed by the front web 25 in the previous work cycle.

FIG. 9 shows a hold-down device 7 of the type described, in anaxonometric representation. Shown clearly are the webs 22 extendingparallel to the production strand, against which the insulating elements21 on both sides bear. The webs 22 are connected to one another via twowebs 25, which extend transversely overall and penetrate the productionstrand when the hold-down device 7 closes. The webs 25 delimit thesection of the production strand that can be deformed in one work cycleof the forming tool. The leads 26 for the heating element, which is notshown, and the associated sensors are disposed laterally on thehold-down device 7.

FIG. 10 shows an axonometric representation of a base plate 5 having amold plate 6 fastened thereon. The webs 14 that laterally delimit a moldsegment 15 protrude from the mold plate 6. The insertable base 12 formsthe base of the mold segments. The selection of the mold segments 15, inthe shape of cheese wedges in this case, defines the shape of theindividual packages.

FIG. 11 shows a production strand of the filled film strip 2 at variouspoints in time of the forming process, which occur one after the otherin the production strand. Cavities 23 are formed in the double-layerfilm strip 2, which is filled with food mass 16 and is sealed by way oftwo longitudinal sealing seams 19, said cavities being separated by asealing area 24 into cavities 23 that are disposed one after the otherand define the individual package 27 of the food mass. The sealing area24 encircling each individual package 27 is sealed by way of ultrasonicsealing means, thereby removing any remaining food mass 16 from thesealing area 24 that has not yet been displaced by the webs 14. In afurther method step, the consecutive individual packages 27 areseparated from one another. In so doing, the film edge regions 20 arecut off in such a way that a remaining film edge region of the two filmlayers 17, 18 forms an opening tab 28 for the individual package 27.

1. A method for the portioned packaging of an at least substantiallyincompressible food mass (16), more particularly of processed cheese,which is filled as a flowable mass into a tubular wrapping comprising athermoplastic plastic film, wherein the thermoplastic plastic film ofthe wrapping (2) enclosing the food mass (16) is shaped in a mold intoindividual units (23), each defining a portion, with displacement of thefood mass out of sealing areas, in that the units (23) disposed onebehind the other are delimited with respect to each other in the sealingarea (24) by way of sealing and are subsequently separated from oneanother.
 2. The method according to claim 1, wherein a vacuum thatsuctions the plastic film into the mold is generated in a forming means(1) in order to support the shaping of a unit (23) in the film layer(17, 18).
 3. The method according to claim 2, wherein the vacuum isgenerated after one segment (7) of the forming means (1) has been movedcompletely into the food mass (16) enclosed by the film strip (2). 4.The method according to claim 1, wherein the sealing is carried outusing ultrasound, wherein parts of the forming means are used asultrasonic generators (“sonotrodes”).
 5. The method according to claim4, wherein the portions are separated from one another by cuts in thesealing area.
 6. The method according to claim 1, wherein the tubularwrapping is formed by a film strip (2) sealed on the longitudinal side,wherein adjacently disposed film edge regions (20) remain, which formthe opening tabs (27) for the individual package (27).
 7. A device forthe portioned packaging of a flowable, at least substantiallyincompressible food mass (16), comprising: filling means for filling atubular wrapping comprising a thermoplastic plastic film with theflowable food mass (16), forming means (1) for creating units (23), eachdefining a portion, from the wrapping (2), wherein the forming means (1)comprises mold segments (15) for forming consecutive units (23) having aspecifiable shape in the film strip (2), sealing means for creatingsealing areas (24) delimiting the units (23), each forming a portion,and cutting means for separating portions.
 8. The device according toclaim 7, wherein the sealing means comprises a sonotrode for theultrasonic sealing of the sealing area (24).
 9. The device according toclaim 7, wherein the forming means (12) comprises means for generating avacuum in the mold segments (15).
 10. Packaging for an at leastsubstantially incompressible food mass (16) manufactured according tothe method of claim 1.